Projector

ABSTRACT

A first holding barrel, a first mirror bending a first optical axis of the first holding barrel at 90°, a second holding barrel, a second mirror bending a second optical axis of the second holding barrel at 90°, and a third holding barrel are disposed on an optical axis from a screen side to an image forming panel. A first connection member connects the first holding barrel including the first mirror to the second holding barrel to be rotationally movable in increments of 90°. A second connection member connects the second holding barrel and the second mirror to the third holding barrel to be rotationally movable in increments of 90°. An orientation of a display image of the image forming panel is changed based on rotational movement states of an optical axis of a first sensor and an optical axis of a second sensor to make an orientation of a projection image on the screen match an original image.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of copending U.S. application Ser.No. 16/887,761, filed on May 29, 2020, which is a Continuation of PCTInternational Application No. PCT/JP2018/043922 filed on 29 Nov. 2018,which claims priority wider 35 U.S.C § 119(a) to Japanese PatentApplication No. 2017-230955 tiled on 30 Nov. 2017. The aboveapplications are hereby expressly incorporated by reference, in theirentirety, into the present application.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a projector.

2. Description of the Related Art

In recent years, a projector in which an image forming panel, such as aliquid crystal display element or a digital micromirror device (DMD:Registered Trademark), is mounted has become widespread.

Recently, with the widespread use of smartphones and the like, inaddition to landscape imaging with a horizontally long imaging screen,portrait imaging with a vertically long imaging screen is also easilyperformed. For this reason, opportunities are increasing for projectorsto project a screen in which a landscape screen and a portrait screenare mixed. There is also increasing demand for projection of a portraitscreen in signage applications as advertising mediums, such assignboards.

For this reason, a projector that rotates a projection direction at 90°within a horizontal plane using a reflection mirror and switches betweenportrait projection with a vertically long screen and landscapeprojection with a horizontally long screen has been suggested (seeJP2014-170097 A).

SUMMARY OF THE INVENTION

However, in JP2014-170097A, the reflection mirror is externally attachedto a projection lens, there is a need to use a large reflection mirror,and there is a problem in that the device is increased in size.

The invention has been accomplished in view of the above-describedcircumstances, and an object of the invention is to provide a projectorcapable of performing landscape projection and portrait projection andfreely setting a projection direction without causing an increase insize.

In order to achieve the above-described object, the invention provides aprojector comprising an image forming panel, a projection opticalsystem, a first connection member 44, a first sensor, and a controller.The image forming panel displays an image based on an original image.The projection optical system has, in order from a screen side, a firstoptical system, a first reflection member, and a second optical system,and projects the image displayed on the image forming panel onto ascreen as a magnified image. The first reflection member bends a firstoptical axis of the first optical system at 90°. The first connectionmember 44 connects the first optical system including the firstreflection member to the second optical system to be rotationallymovable in increments of 90° around a second optical axis of the secondoptical system. The first sensor detects a rotational movement state ofthe first optical axis of the first optical system around the secondoptical axis in the first connection member 44. The controller changesan orientation of a display image of the image forming panel based onthe rotational movement state detected by the first sensor to make anorientation of a projection image on a projection plane match theoriginal image.

It is preferable that the projection optical system comprises a secondreflection member and a third optical system. The second reflectionmember bends the second optical axis of the second optical system at90°. The third optical system is disposed on the image forming panelside from the second reflection member.

It is preferable that the projection optical system has a secondconnection member and a second sensor. The second connection memberconnects the second optical system and the second reflection member tothe third optical system to be rotationally movable in increments of 90°around a third optical axis of the third optical system, The secondsensor detects a rotational movement state of the second optical axis ofthe second optical system around the third optical axis in the secondconnection member. The controller changes the orientation of the displayimage of the image forming panel based on the rotational movement statesdetected by the first sensor and the second sensor to make theorientation of the projection image on the projection plane match theoriginal image.

It is preferable that a reflection surface of each of the firstreflection member and the second reflection member is a plane. It ispreferable that the controller determines whether the display image is avertically long portrait image or a horizontally long landscape imagebased on image orientation information to change an orientation of animage. It is preferable that the controller has an image orientationchange input unit that inputs change of an image orientation.

It is preferable that the projector further comprises a projector bodyhaving the image forming panel, and a vertical shift mechanism. Thevertical shift mechanism shifts the projector body in a verticaldirection. It is preferable that the projector comprises a horizontalshift mechanism in addition to or instead of the vertical shiftmechanism. The horizontal shift mechanism shifts the projector body in ahorizontal direction. It is preferable that the projector furthercomprises a projector body having the image forming panel, and arotational movement mechanism that rotationally moves the projector bodyaround a vertical line.

According to the invention, it is simply possible to perform landscapeprojection and portrait projection and to freely set a projectiondirection without causing an increase in size.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing a projector of the invention.

FIG. 2 is a longitudinal sectional view of the projector.

FIG. 3 is a control block diagram.

FIG. 4 is a flowchart of orientation correction of a display screen.

FIG. 5 is a side view showing a bending pattern of a projection opticalsystem.

FIG. 6 is a table illustrating the orientation correction of the displayscreen.

FIG. 7 is a side view showing a bending pattern of a projection opticalsystem in a projector of Modification Example 1 in which a third opticalaxis is arranged in a vertical direction.

FIG. 8 is a table illustrating orientation correction of a displayscreen of Modification Example 1.

FIG. 9 is a side view of a second embodiment having a first connectionmember and a second connection member by motor drive.

FIG. 10 is a control block diagram in the second embodiment.

FIG. 11 is a side view of a third embodiment having a second connectionmember on a projector body side.

FIG. 12 is a side view showing a projector of a fourth embodiment usingone mirror.

FIG. 13 is a perspective view showing a projector of a fifth embodimentthat comprises a pedestal having a shift mechanism.

FIG. 14 is a perspective view showing a projector of a sixth embodimentthat comprises a pedestal having a rotational movement mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

As shown in FIG. 1, a projector 10 of the embodiment comprises aprojection optical system 11 and a projector body 12. The projector body12 has an image forming panel 13, An image is displayed on an imagedisplay surface 13 a of the image forming panel 13 based on an originalimage. The projection optical system 11 projects the image displayed onthe image forming panel 13 onto a screen 15 as a magnified image.

As shown in FIG. 2, the projection optical system 11 comprises, in orderon an optical axis from the screen 15 to the image forming panel 13, afirst optical system 21 having a first optical axis CL1, a secondoptical system 22 having a second optical axis CL2, and a third opticalsystem 23 having a third optical axis CL3. In the embodiment, an up-downdirection, a right-left direction, and a front-rear direction aredetermined based on a state in which the projector body 12 turns aprojection direction in a direction of the third optical axis CL3.

A first mirror 24 as a first reflection member is disposed between thefirst optical system 21 and the second optical system 22. The firstmirror 24 has a reflection surface that is a plane, and bends the firstoptical axis CL1 of the first optical system 21 through reflection toform the second optical axis CL2 that intersects the first optical axisCL1 at 90°. A second mirror 25 as a second reflection member is disposedbetween the second optical system 22 and the third optical system 23.The second mirror 25 has a reflection surface that is a plane, and bendsthe second optical axis CL2 through reflection to form the third opticalaxis CL3 that intersects the second optical axis CL2 at 90°.

The first optical system 21 has a first lens 31 and a second lens 32 inorder on the first optical axis CL1 from the screen 15 to the imageforming panel 13. The second optical system 22 has a third lens 33 and afourth lens 34 on the second optical axis CL2. The third optical system23 has a fifth lens 35 and a sixth lens 36 on the third optical axisCL3, Although each of the first lens 31, the second lens 32, the thirdlens 33, the fifth lens 35, and the sixth lens 36 is shown as a singlelens for simplification of illustration, each lens actually consists ofa plurality of lens groups. The sixth lens 36 and the fifth lens 35image illumination light from the image forming panel 13 on an imagingplane 37 as an intermediate image. The fourth lens 34, the third lens33, the second lens 32, and the first lens 31 project the image of theimaging plane 37 onto the screen 15 on a magnified scale.

The first optical system 21, the second optical system 22, the thirdoptical system 23, the first mirror 24, and the second mirror 25 arestored in a lens barrel 26. The lens barrel 26 has a first holdingbarrel 41, a second holding barrel 42, a third holding barrel 43, afirst connection member 44. and a second connection member 45, and themembers 41 to 45 are assembled integrally.

The first holding barrel 41 has a first lens frame 41 a, a second lensframe 41 b, and a first mirror frame 41 c. The first lens frame 41 a isformed in a cylindrical shape, and the first lens 31 is fixed to thefirst lens frame 41 a. The second lens frame 41 b is formed in acylindrical shape, and the second lens 32 is fixed to the second lensframe 41 b. The first mirror frame 41 c is formed in an angular tubularshaped having an inclined surface 46, and has a connection barrel 47 ina lower portion. The first mirror 24 is fixed to the inner surface ofthe inclined surface 46, and the third lens 33 and the fourth lens 34are fixed to the connection barrel 47.

The second holding barrel 42 has a connection barrel member 42 a and asecond mirror frame 42 b. The connection barrel member 42 a isexternally fitted to the connection barrel 47 of the first holdingbarrel 41, and both of the connection barrel member 42 a and theconnection barrel 47 are rotationally movably connected. The firstconnection member 44 is constituted by the fitting structure of theconnection barrel member 42 a and the connection barrel 47. The secondmirror frame 42 b is formed in an angular tubular shape having aninclined surface 50, and has a connection barrel 51 in a side portion.The second minor 25 is fixed to the inner surface of the inclinedsurface 50.

The third holding. barrel 43 is formed in a stepped cylindrical shape,and has a fourth lens frame 43 a, a flange 43 b, and a fifth lens frame43 c. The fifth lens 35 is fixed to the fourth lens frame 43 a. Thefourth lens frame 43 a is internally fitted to the connection barrel 51of the second holding barrel 42, and both of the fourth lens frame 43 aand the connection barrel 51 are rotationally movably connected. Thesecond connection member 45 is constituted by the fitting structure ofthe fourth lens frame 43 a and the connection barrel 51 of the secondholding barrel 42. The flange 43 b is fixed to a lens mounting hole 62 aof a housing 62. The sixth lens 36 is fixed to the fifth lens frame 43c.

The first connection member 44 connects the first holding barrel 41 tothe second holding barrel 42 to be rotationally movable in increments of90° around the second optical axis CL2 of the second optical system 22.Similarly, the second connection member 45 connects the second holdingbarrel 42 to the third holding barrel 43 to be rotationally movable inincrements of 90° around the third optical axis CL3 of the third opticalsystem 23. For this reason, the first connection member 44 is providedwith a first click mechanism and a first sensor 55 (see FIG. 3). Thesecond connection member 45 is provided with a second click mechanismand a second sensor 56 (see FIG. 3). The first connection member 44 andthe second connection member 45 should rotationally movably connect bothmembers, and various rotationally movable guide mechanisms can be used.

The first click mechanism is constituted of a known click mechanism. Thefirst click mechanism is configured such that one protrusion is lockedto another storage portion each time the first holding barrel 41 isrotationally moved at 90° with respect to the second holding barrel 42.With this, the rotational movement of the first holding barrel 41 isregulated in increments of 90°. Then, the first holding barrel 41 isrotationally moved with force beyond the rotational movement regulation,whereby the first click mechanism is unlocked, and next rotationalmovement is possible. In a case where the first holding barrel 41 isfurther rotationally moved at 90° in this state, rotational movement isregulated at a next click position.

The first sensor 55 detects a rotational movement state of the firstoptical axis CL1 of the first optical system 21 around the secondoptical axis CL2 in the first connection member 44. The rotationalmovement state refers to four states of an initial position where thefirst optical axis CL1, the second optical axis CL2, and the thirdoptical axis CL3 are in a U shape, a 90° position rotationally movedclockwise at 90° from the initial position, a 180° position furtherrotationally moved clockwise at 90° from the 90° position, and a 270°position further rotationally moved clockwise at 90° from the 180°position. Although a mechanical sensor is used as the first sensor 55,an optical sensor, a detection sensor of a rotational movement angle bya rotary encoder, or the like may be used.

The second click mechanism regulates rotational movement of the secondholding barrel 42 each time the second holding barrel 42 is rotationallymoved at 90° with respect to the third holding barrel 43. As the secondclick mechanism, similarly to the first click mechanism, a known clickmechanism is used. The first connection member 44 and the secondconnection member 45 have rotational movement regulation members,respectively, The rotational movement regulation members regulaterotational movement beyond 360° in the respective connection members 44and 45.

The lens configuration of the first lens 31 to the sixth lens 36 isdescribed in detail, for example, in “Projection Optical System andProjection Display Device” of JP2016-156986A (corresponding toUS2016/246037A1), JP2016-156983A (corresponding to US2016/246034A1), orthe like. The optical systems described in the documents can be used asthe projection optical system 11. With the projection optical systemsand the projection display devices, an optical system having highprojection performance of which aberrations are satisfactorily correctedat a wide angle is obtained.

As shown in FIG. 1, the projector body 12 has a light source 63, animage forming panel 13, and a controller 69 stored in the housing 62substantially having a rectangular parallelepiped shape. The projectorbody 12 has a square longitudinal section and is formed in a rectangularparallelepiped shape as a whole to have a size in which the corners ofthe projector body 12 are positioned inside the rotational movementrange of the first holding barrel 41 around the third optical axis CL3.Accordingly, even though the second holding barrel 42 is rotationallymoved, the first holding barrel 41 does not come into contact with theprojector body 12.

As the image forming panel 13, for example, a transmissive liquidcrystal panel is used. The light source 63 is disposed on a rear surfaceof the image forming panel 13, that is, on an opposite side of the imageforming panel 13 from the projection optical system 11. The light source63 uses a light emitting diode (LED) that emits light of three colors ofred (R), green (G), and blue (B) simultaneously, and illuminates theimage forming panel 13. Instead of an LED, a xenon lamp, a halogen lamp,an ultra-high pressure mercury lamp, or the like that emits white lightmay be used. The projection optical system 11 projects illuminationlight from the image forming panel 13 illuminated by the light source 63onto the screen 15.

As shown in FIG. 3, the controller 69 has an image processing unit 70,an image orientation determination unit 71, an image memory 72, a paneldrive unit 73, a light source drive unit 74, and an image orientationchange button 75 as an image orientation change input unit. The imageprocessing unit 70 executes image processing on a projection image fromthe image memory 72 and sends an image signal to the panel drive unit73. The panel drive unit 73 drives the image forming panel 13 based onthe image signal to display an image of three colors of RGB on the imagedisplay surface 13 a. The light source drive unit 74 turns on the lightsource 63.

The image orientation determination unit 71 corrects an orientation ofan image displayed on the image forming panel 13 based on signals of thefirst sensor 55 and the second sensor 56. In a case where the imageorientation change button 75 is pressed, the image orientationdetermination unit 71 sequentially changes the orientation of the image.

FIG. 4 is a flowchart showing image orientation correction in thecontroller 69. The image orientation determination unit 71 detects anoptical axis bending state of the projection optical system 11 based onthe signals of the first sensor 55 and the second sensor 56. As shown ina second row of a table of FIG. 6, a relationship between a paneldisplay image E1, which is displayed on the image forming panel 13, andan orientation of each of projection images E21 to E24 of the screen 15in a bending state of the projection optical system 11 is known inadvance. Accordingly, the bending state of the projection optical system11 is specified from among 16 patterns shown in FIG. 5 based onrotational movement detection states from the first sensor 55 and thesecond sensor 56. Then, as shown in the table of FIG. 6, an imageorientation correction value is specified based on the specified bendingpattern, and the specified image orientation correction value is sent tothe image processing unit 70. The image processing unit 70 changes anorientation of an original image E0 based on the image orientationcorrection value, and displays panel display images E1 and E11 to E18 onthe image forming panel 13. The panel display images E1 and E11 to E18are changed in orientation by the two mirrors 24 and 25 to have the sameorientation as the original image E0 and are projected onto the screen15. For this reason, the image orientation determination unit 71 hastable data 76 as the table of FIG. 6 that stores an optical axis bendingstate of the projection optical system 11 in association with anorientation correction value of an image, which is displayed on theimage forming panel 13 in the bending state.

FIG. 5 shows all bending patterns of the projection optical system 11that are obtained when the first holding barrel 41 and the secondholding barrel 42 are individually rotationally moved in increments of90° using the first connection member 44 and the second connectionmember 45. A state of the projection optical system 11 of a bendingpattern (AA) is an initial state, and the optical axis is bent in a Ushape. The bending patterns obtained when the first holding barrel 41 isrotationally moved in order in increments of 90° clockwise from (AA)with respect to the second holding barrel 42 are (AB), (AC), and (AD).The bending patterns obtained when the first holding barrel 41 issimilarly rotationally moved in order in increments of 90° clockwisefrom (BA) are (BB), (BC), and (BD), the bending patterns obtained whenthe first holding barrel 41 is similarly rotationally moved in order inincrements of 90° clockwise from (CA) are (CB), (CC), and (CD), and thebending patterns obtained when the first holding barrel 41 is similarlyrotationally moved in order in increments of 90° clockwise from (DA) are(DB), (DC), and (DD).

The bending patterns obtained when the second holding barrel 42 isrotationally moved in order in increments of 90° clockwise from (AA)with respect to the third holding barrel 43 are (BA), (CA), and (DA).The bending patterns obtained when the second holding barrel 42 issimilarly rotationally moved in order in increments of 90° clockwisefrom (AB) are (BB), (CB), and (DB). The bending patterns obtained whenthe second holding barrel 42 is similarly rotationally moved in order inincrements of 90° clockwise from (AC) are (BC), (CC), and (DC). Thebending patterns obtained when the second holding barrel 42 is similarlyrotationally moved in order in increments of 90° clockwise from (AD) are(BD), (CD), and (DD). In this way, the 16 bending state patterns of (AA)to (DD) can be constituted by the first connection member 44 and thesecond connection member 45.

FIG. 6 is a table showing change in an image orientation in therespective bending patterns (AA) to (DD), in the bending form of (AA),in order to make the orientation of the projection image E21 of thescreen 15 be the same as the original image E0, an image formed byrotating the original image E0 at 180° as a mirror image is displayed onthe image forming panel 13 as the panel display image E1. In a casewhere the first holding barrel 41 is rotationally moved in increments of90° in a state in which the orientation of the image is unchanged andorientation correction is not performed, the panel display image isrotated like the screen projection images E21 to E24 in the second rowof the table of FIG. 6.

For example, the screen projection image E22 becomes a portrait imagerotated counterclockwise at 90° in (AB), the screen projection image E23becomes an upside-down landscape image rotated counterclockwise at 180°in (AC), and the screen projection image E24 becomes a portrait imagerotated counterclockwise at 270° in (AD). Accordingly, it is notpreferable that the original image E0 is projected onto the screen 15 ina rotated state like the screen projection images E22, E23, and E24.Therefore, the image is displayed in a state in which the orientation ofthe image is corrected like the panel display images E11, E12, E13, andE14 in a lower section of a third row of the table of FIG. 6. With this,as in an upper section of the third row, screen projection images E31,E32, E33, and E34 with the same orientation (the top, bottom, right, andleft are the same) of the original image E0 are displayed. The imageforming panel 13 is in landscape in (AB) and (CB) or (AD) and (CD). Forthis reason, the screen projection images E32 and E34 are displayed on areduced scale because a horizontal side length of the original image isdisplayed in alignment with a vertical side length of the image formingpanel 13.

A fourth row of the table of FIG. 6 shows correction in a case where theoriginal image is a portrait image. As shown in a lower section of thefourth row, correction is performed to the panel display images E15,E16, E17, and E18 formed by correcting the orientation of the displayimage of the image forming panel 13, whereby screen projection imagesE35, E36, E37, and E38 are displayed as an image with the sameorientation as the original image EU as shown in an upper section of thefourth row.

Projection toward a floor is performed in (BB) and (DD), and projectiontoward a ceiling is performed in (BD) and (DB). In such projectiontoward the ceiling or the floor, since the orientation of the projectionimage is changed depending on a portion to be a reference, in theembodiment, the correction of the image orientation is not particularlyperformed. However, the correction of the image orientation may bearbitrarily performed.

In a case where the orientation of the screen projection image isdesired to be changed, the image orientation change button 75 isoperated. In a case where the image orientation change button 75 ispressed, the orientation of the panel display image E1 displayed on theimage forming panel 13 is sequentially changed for each one operation.For example, the panel display images E11 to E14 shown in the lowersection of the third row of the table of FIG. 6 or the panel displayimages E15 to E18 shown in the lower section of the fourth row of thetable of FIG. 6 are sequentially displayed on the image forming panel13.

Next, the operation of the embodiment will be described. In a case wherethe projection direction should be changed, a user holds the firstholding barrel 41 and rotationally moves the first holding barrel 41around the second optical axis CL2 with the first connection member 44.The user holds the second holding barrel 42 to rotationally move thesecond holding barrel 42 around the third optical axis CL3 with thesecond connection member 45. With the rotational movement operations, asshown in FIG. 5, it is possible to change the projection optical system11 in the 16 bending patterns (AA) to (D), and arbitrarily change theprojection direction.

In FIG. 5, the bending pattern (AA) becomes an upper rear projectionposition, (BA) and (DA) becomes a middle rear projection position, (CA)becomes a lower rear projection position, (AB) becomes an upper leftprojection position, (BB) becomes a lower bottom projection position,(CB) becomes a lower right projection position, (DB) becomes an uppertop projection position, (AC) becomes an upper front projectionposition, (BC) and (DC) become a middle front projection position, (CC)becomes a lower front projection position, (AD) becomes an upper rightprojection position, (BD) becomes an upper top projection position, (CD)becomes a lower left projection position, and (DD) becomes a lowerbottom projection position. Then, with the image orientation correctionby the image orientation determination unit 71 and the image processingunit 70, the projection image onto the screen 15 is projected constantlyin the same orientation as the original image. In a case where aportrait image is mixed in the original image in addition to a landscapeimage, it is possible to press the image orientation change button 75 tosequentially change the orientation of the projection image.

As described above, in the embodiment, in a case where the first holdingbarrel 41 is rotated in increments of 90° by the first connection member44 or the second holding barrel 42 is rotated in increments of 90° bythe second connection member 45, it is possible to simply change theprojection direction. Besides, even though the projection direction ischanged, with the image orientation correction by the image orientationdetermination unit 71 and the image processing unit 70, it is possibleto display the image in the same orientation as the original image E0like the screen projection images E31 to E38 shown in FIG. 6.

Modification Example 1

In the above-described embodiment, although the original image isdisplayed and the orientation of the screen projection image iscorrected with a manual operation while automatic determinationregarding whether the display image is a landscape image or a portraitimage is not performed, instead or in addition, as shown in FIG. 3,determination may be made whether or not the display image is alandscape image or a portrait image using image orientation informationof the original image from the image memory 72, and accordingly, theimage orientation correction may be automatically performed as shown inthe table of FIG. 6.

Modification Example 2

In the above-described embodiment, although an example where theprojector is provided in such a manner that the second optical axis CL2is arranged in the vertical direction has been described, as inModification Example 2 shown in FIGS. 7 and 8, the projector may beprovided in such a manner that the third optical axis CL3 is arranged inthe vertical direction. FIG. 7 shows the same arrangement as thehorizontal arrangement of FIG. 5 excluding that the projector isarranged vertically, and as in FIG. 5, 16 kinds of bending patterns (AA)to (DD) obtained. In this case, as shown in a table of FIG. 8, it isalso possible to simply change the projection direction.

In the above-described embodiment, although the image forming panel isdisposed eccentrically with respect to the third optical axis CL3, thethird optical axis CL3 may be projected in alignment with a centerposition of the projection image of the image forming panel 13. One orboth of the image forming panel 13 and the projection optical system 11may be shifted by a shift mechanism in a direction perpendicular to thethird optical axis CL3.

In the above-described embodiment, the second optical axis is made to berotationally movable in the whole circumferential direction of the thirdoptical axis CL3 using the housing 62 substantially in a rectangularparallelepiped shape having a square longitudinal section. Instead,though not shown, the invention may be carried out to a projector inwhich a projection optical system is disposed in a deflected manner onone side surface of a rectangular housing having a square longitudinalsection because of the arrangement of a light source and the like. Inthis case, while the housing and the first optical system interfere witheach other, and the projection direction is restricted as much, it ispossible to perform portrait projection and landscape projection.

Second Embodiment

In the above-described embodiment, although the first holding barrel 41or the second holding barrel 42 is rotationally moved manually, instead,in a projector 80 of a second embodiment shown in FIGS. 9 and 10, thefirst connection member 44 and the second connection member 45 arerotationally moved by gear drive of a first motor 81 and a second motor82.

In the following embodiment, the same constituent members as those inthe first embodiment are represented by the same reference numerals, andoverlapping description will not be repeated. In the second embodiment,a first switch 85 and a second switch 86 are connected to a controller79. The first motor 81 is rotated by a first motor drive unit 87 with anoperation of the first switch 85. With this, the first connection member44 is rotated, whereby the orientation of the first optical system 21can be chanced.

The second motor 82 is rotated by a second motor drive unit 88 with anoperation of the second switch 86. With this, the second holding barrel42 is rotated, whereby the orientation of the second optical system 22can be chanced.

The first sensor 55 and the second sensor 56 may be omitted. In thiscase, for example, the number of drive pulses corresponding to an amountof rotation of each of the motors 81 and 82 is counted to detect arotational movement angle of the first optical system 21 or the secondoptical system 22. Instead of or in addition to counting the number ofdrive pulses of each of the motors 81 and 82, a rotational movementangle of a gear may be detected by a rotation detection plate and asensor (not shown). In this case, for example, the rotation detectionplate having a number of notches at given pitches is fixed to an outercircumferential surface of the gear, and passing of a large number ofnotches is detected by a photointerrupter to obtain the rotationalmovement angle.

Third Embodiment

In the second embodiment, although the second holding barrel 42 is heldby the second connection member 45 to be rotationally movable withrespect to the third holding barrel 43, instead of the second connectionmember 45, as in a third embodiment shown in FIG. 11, a mount rotationalmovement unit 91 may be provided in a projector body 90. The mountrotational movement unit 91 has the same basic configuration as thesecond connection member 45, and the same constituent members arerepresented by the same reference numerals. In the third embodiment, amount 92 is rotated by a motor 82, whereby the second holding barrel 42can be rotated around the third optical axis CL3.

Fourth Embodiment

In the first embodiment, although the two mirrors 24 and 25 are used, ina projector of a fourth embodiment shown in FIG. 12, the second mirror25 is removed and only the first mirror 24 is used, thereby constitutinga projection optical system 96 in which an optical axis is in an Lshape. For this reason, a cylindrical second holding barrel 97 isprovided instead of the second holding barrel 42 of the first embodimentsubstantially formed of a rectangular parallelepiped angular tube. Theconfiguration of the fourth embodiment is the same as in the firstembodiment excluding that the second mirror 25 of the first embodimentis removed and the second holding barrel 97 is formed in a cylindricalshape, and the same constituent members as those in the first embodimentare represented by the same reference numerals.

Fifth Embodiment

In the first embodiment, the projection position of the projection imagefluctuates with change in bending state of the projection optical system11. In order to avoid the fluctuation, in a projector 100 of a fifthembodiment shown in FIG. 13, a projector body 12 is shifted using apedestal 103 having shill mechanisms 101 and 102, thereby eliminatingthe fluctuation of the projection position. For this reason, change inprojection position by the first connection member 44 and the secondconnection member 45, the projector body 12 is shifted a vertical shiftmechanism 101 and a horizontal shift mechanism 102 by an amount ofmovement of the projection position. It is possible to eliminate themovement of the first optical axis CL1 in the vertical direction due torotational movement of the second optical axis CL2 by the vertical shiftmechanism 101, and to project the projection image at an invariablyconstant height. It is possible to eliminate the movement of the firstoptical axis CL1 in the horizontal direction due to the rotationalmovement of the second optical axis CL2 by the horizontal shiftmechanism 102, and to invariably align the first optical axis CL1 as aprojection optical axis with the center of the screen 15. One of thevertical shift mechanism 101 or the horizontal shift mechanism 102 maybe omitted, and only the shift in the vertical direction or only theshift in the horizontal direction may be performed.

Sixth Embodiment

In the sixth embodiment, although the pedestal 103 is moved up and downby the shift mechanisms 101 and 102, in addition, as shown in FIG. 14,the pedestal 103 may be rotationally moved around a vertical linecentering on the second optical axis CL2 by a rotational movementmechanism 105. The rotational movement may be in increments of 90° ormay be in increments of other angles. The rotational movement center ofthe pedestal 103 should not be aligned with the second optical axis CL2,and should be a vertical line parallel to the second optical axis CL2.The rotational movement may be performed manually in addition to motordrive. Instead of providing the rotational movement mechanism 105 inaddition to the shift mechanisms 101 and 102, only the rotationalmovement mechanism 105 may be simply provided or the rotational movementmechanism 105 may be provided in the pedestal 103 having either of theshift mechanism 101 or 102. The rotational movement mechanism 105 isprovided, whereby projection can be performed in all directions of ahorizontal plane while the portrait screen or the landscape screen ismaintained.

In the respective embodiments, although a transmissive liquid crystalpanel is used as the image forming panel 13, a reflective liquid crystalpanel may be used. In this case, the light source 63 is disposed on thefront surface side of the image forming panel 13 to perform simultaneousirradiation of irradiation light of three colors of RGB. In a case wherea DMD is used as the image forming panel 13, for example, the lightsource 63 is disposed on the front surface side of the image formingpanel 13 to emit LED of three colors of RGB in a time-division manner insynchronization with a forming timing of a three-color image of the DMD.

In the respective embodiments, although description has been providedbased on an example where the projector 10 is provided on a table, theinvention can also be applied to a case where the projector is usedwhile being suspended from a ceiling or the like. Furthermore, althoughan example where an image is projected onto the screen 15 has beendescribed, a projection plane is not limited to the screen 15, and theprojector can be used as a projector that projects an image on variousprojection planes.

In the respective embodiments, terms, such as perpendicular andparallel, have been used to represent a positional relationship betweenthe plurality of optical axes or specific numerical values of an angle,such as 90°, have been used for description. However, the terms or thenumerical values include a range to be allowed with an error based onaccuracy required for the optical system.

In the respective embodiments, although the projector in which theprojection optical system 11 is fixed to the housing 62 has beendescribed, the projection optical system 11 may be attachably anddetachably mounted in the projector body 12. In a case where aninterchangeable projection optical system 11 is used, for example, apart of lenses of the first optical system 21, for example, the firstlens 31 and the second lens 32 may be provided in the projector body,and the number of lenses on the projection optical system 11 side may bedecreased.

EXPLANATION OF REFERENCES

10: projector

11: projection optical system

12: projector body

13: image forming panel

13 a: image display surface

15: screen

21: first optical system

22: second optical system

23: third optical system

24: first mirror

25: second mirror

26: lens barrel

31: first lens

32: second lens

33: third lens

34: fourth lens

35: fifth lens

36: sixth lens

37: imaging plane

41: first holding barrel

41 a: first lens frame

41 b: second lens frame

41 c: first mirror frame

42: second holding barrel

42 a: connection barrel member

42 b: second mirror frame

43: third holding barrel

43 a: fourth lens frame

43 b: flange

43 c: fifth lens frame

44: first connection member

45: second connection member

46: inclined surface

47: connection barrel

50: inclined surface

51: connection barrel

55: first sensor

56: second sensor

62: housing

62 a: lens mounting hole

63: light source

69: controller

70: image processing unit

71: image orientation determination unit

72: image memory

73: panel drive unit

74: light source drive unit

75: image orientation change button

76: table data

79: controller

80: projector

81: first motor

82: second motor

85: first switch

86: second switch

87: first motor drive unit

88: second motor drive unit

90: projector body

91: mount rotational movement unit

92: mount

96: projection optical system

97: second holding barrel

100: projector

101: vertical shift mechanism

102: horizontal shift mechanism

103: pedestal

105: rotational movement mechanism

CL1: first optical axis

CL2: second optical axis

CL3: third optical axis

E0: original image

E1, E11 to E18: panel display image

E21 to E24, E31 to E38: screen projection image

1. A projector comprising: an image forming panel that displays an image based on an original image; a projector body having the image forming panel; a projection optical system that connects to the projector body and has, in order from a screen side, a first optical system, a first reflection member bending a first optical axis of the first optical system, and a second optical system, and projects the image displayed on the image forming panel onto a screen as a magnified image; a first connection member that connects the first optical system including the first reflection member to the second optical system to be rotationally movable around a second optical axis of the second optical system; a first sensor that detects a rotational movement state of the first optical axis of the first optical system around the second optical axis in the first connection member; and a controller that changes an orientation of a display image of the image forming panel based on the rotational movement state detected by the first sensor to make an orientation of a projection image on a projection plane match the original image, wherein the projector is provided in a horizontal installation mode that a longitudinal direction of the projector body is arranged in a horizontal direction or in a vertical installation mode that the longitudinal direction of the projector body is arranged in a vertical direction, and wherein the controller performs a correction fir changing the orientation of the projection image, in a different manner between the vertical installation mode and the horizontal installation mode.
 2. The projector according to claim 1, wherein the first connection member regulates the rotation of the first reflection member and the first optical system in increments of a predetermined angle.
 3. The projector according to claim 1, wherein the first connection member regulates the rotation of the first reflection member and the first optical system in increments of 90°.
 4. The projector according to claim 1, wherein a reflection surface of each of the first reflection member and the second reflection member is a plane.
 5. The projector according to claim 1, wherein the controller determines whether the display image is a vertically long portrait image or a horizontally long landscape image based on image orientation information to change an orientation of an image.
 6. The projector according to claim 1, wherein the controller has an image orientation change input unit that inputs change of an image orientation.
 7. The projector according to claim 1, further comprising: a shift mechanism that shifts one or both of the image forming panel and the projection optical system in the vertical direction.
 8. The projector according to claim 1, wherein the rotation of the first connecting member is regulated at a first position and a second position, and the second position is a position rotated by 90° about the second optical axis from the first position.
 9. The projector according to claim 1, wherein in a case where the second optical system and the second reflection member are not rotated by the second connecting member and the first optical system and the first reflection member are rotated by 90° by the first connecting member, the direction of the long side of the display image is rotated by 90°.
 10. The projector according to claim 2, wherein the controller determines whether the display image is a vertically long portrait image or a horizontally long landscape image based on image orientation information to change an orientation of an image.
 11. The projector according to claim 3, wherein the controller determines whether the display image is a vertically long portrait image or a horizontally long landscape image based on image orientation information to change an orientation of an image.
 12. The projector according to claim 4, wherein the controller determines whether the display image is a vertically long portrait image or a horizontally long landscape image based on image orientation information to change an orientation of an image.
 13. The projector according to claim 2, further comprising: a shift mechanism that shifts one or both of the image forming panel and the projection optical system in the vertical direction.
 14. The projector according to claim 3, further comprising: a shift mechanism that shifts one or both of the image forming panel and the projection optical system in the vertical direction.
 15. The projector according to claim 4, further comprising: a shift mechanism that shifts one or both of the image forming panel and the projection optical system in the vertical direction.
 16. The projector according to claim 5 further comprising: a shift mechanism that shifts one or both of the image forming panel and the projection optical system in the vertical direction.
 17. The projector according to claim 6, further comprising: a shift mechanism that shifts one or both of the image forming panel and the projection optical system in the vertical direction.
 18. The projector according to claim 2, wherein in a case where the second optical system and the second reflection member are not rotated by the second connecting member and the first optical system and the first reflection member are rotated by 90° by the first connecting member, the direction of the long side of the display image is rotated by 90°.
 19. The projector according to claim 3, wherein in a case where the second optical system and the second reflection member are not rotated by the second connecting member and the first optical system and the first reflection member are rotated by 90° by the first connecting member, the direction of the long side of the display image is rotated by 90°.
 20. The projector according to claim 4, wherein in a case where the second optical system and the second reflection member are not rotated by the second connecting member and the first optical system and the first reflection member are rotated by 90° by the first connecting member, the direction of the long side of the display image is rotated by 90°. 